AGN Obscuring Tori Supported by Infrared Radiation Pressure

Explicit 2-d axisymmetric solutions are found to the hydrostatic equilibrium,energy balance, and photon diffusion equations within obscuring tori aroundactive galactic nuclei. These solutions demonstrate that infrared radiationpressure can support geometrically thick structures in AGN environments subjectto certain constraints: the bolometric luminosity must be roughly 0.03--1 timesthe Eddington luminosity; and the Compton optical depth of matter in theequatorial plane should be order unity, with a tolerance of about an order ofmagnitude up or down. Both of these constraints are at least roughly consistentwith observations. In addition, angular momentum must be redistributed so thatthe fractional rotational support against gravity rises from the inner edge ofthe torus to the outer in a manner specific to the detailed shape of thegravitational potential. This model also predicts that the column densitiesobserved in obscured AGN should range from about 10^{22} to about 10^{24}cm^{-2}.Comment: ApJ, in pres